What might cause increased latency in a nerve conduction study?

Increased latency in a nerve conduction study is primarily caused by conditions that affect the myelin sheath surrounding the nerve fibers. When there is nerve compression, demyelination, or lesions, the electrical impulses traveling along the nerve fibers can slow down. Myelin is essential for rapid signal conduction; it acts as insulation around the nerve fibers. When the myelin is damaged or compressed, the nerve's ability to quickly transmit signals is impaired, resulting in longer latency times.

In this context, conditions such as carpal tunnel syndrome (caused by compression of the median nerve at the wrist) or multiple sclerosis (which causes widespread demyelination) would lead to measurable increases in nerve conduction latency. The other factors listed do not have the same significant impact on latency. For instance, increased nerve fiber diameter could actually speed up conduction, while excessive exercise or poor circulation would more likely affect strength and amplitude rather than directly causing increased latency.